What is moral and what isn't changes with the times. For example, blaspheming could get you murdered by the state in medieval times. The colonies had different views of morality, especially religious morality. It was immoral to work on the Sabbath. It was immoral to have sex before marriage.

The Founders saw fit to abolish the nobility, and disassociated religion from government. We've forgotten what an enormous leap both of those were (each of the colonies had an establishment of religion). I've seen endless documentaries on the founding of the country, and there's no mention of either of these.

Half of the colonies did abolish slavery. But, again, if it was demanded of the other half, the Union would never have happened.

Jefferson, Franklin, and Washington all held slaves.

I am certainly not advocating slavery. I'm merely pointing out that people should be judged on the morality of their times, not today's morality. If we judged past people by our modern standards, they would all be condemned.